Uniformly hardened throughout, they hold the edge when cutting difficult-to-machine alloys, maintaining straightness of cut. Ideal for use when the workpiece is held securely and the blade is not subjected to bending and twisting stresses. Blade cross section 13 x 0.65 mm (1/2 x 0.25 Inch).Length: 300mm (12 Inch)Size 300 (12 in) x 18 tpi Pack of 50 blades